text: *Ac for the acetyl group (Ac is also the symbol for the element actinium. However, actinium is almost never encountered in organic chemistry, so the use of Ac to represent the acetyl group never causes confusion);
  *Bz for the benzoyl group; OBz is the benzoate group
  *Piv for the pivalyl (t-butylcarbonyl) group; OPiv is the pivalate group
  *Bt for the 1-benzotriazolyl group
  *Im for the 1-imidazolyl group
  *NPhth for the phthalimide-1-yl group